Investigation of the mechanism for selective flocculation process using natural iron ore tailings

Abstract

A huge quantity of iron ore tailings was generated every year from the iron ore washing plants during beneficiation. These discarded tailings were stored in the tailing pond. Safe storage and handling of these tailings are a major concern to the management. Due to depletion of high-grade ore, the government of India had reduced the cut-off grade from 55 to 45% because of the shortage of the iron ore reserves. Ultrafine particles present in the tailings cannot be treated effectively by the conventional methods due to particle size limitations. For Indian iron ore, associated gangue mineral alumina is the major source which causes problems in the blast furnace. Removal of alumina from the iron ore of ultrafine size is a hill task. A selective flocculation approach was employed to the iron ore tailings which contain 50.98% of Fe (T) with 8.86% of Al2O3 assay. It was observed that, when applying a selective flocculation process, the concentrate contains more than 63.48% Fe (%), 2.5% Al2O3 with 31.196% recovery (%). The mechanism was investigated using zeta potential analysis, FTIR analysis, etc.